CHAPTER 13: CARDIOVASCULAR DIAGNOSTIC PROCEDURES {Urden: Critical Care Nursing, 9th Edition}

C HAPTER 13: C ARDIOVASCULAR
D IAGNOSTIC P ROCEDURES
Urden: Critical Care Nursing, 9th Edition



MULTIPLE CHOICE


1. Which of the electrocardiogram (ECG) findings would be positive for an
inferior wall m yocardial infarction (MI)?
a. ST segment depression in leads I, aVL, and V2 to V4
b. Q waves in leads V1 to V2
c. Q waves in leads II, III, and aVF
d. T-wave inversion in leads V4 to V6, I, and aVL



ANS: C



Abnormal Q waves develop in leads overlying the affected area. An
inferior wall infarction is seen with changes in leads II, III, and aVF.
Leads I and aVF are selected to detect a sudden change in ventricular
axis. If ST segment monitoring is required, the lead is selected
according to the area of ischemia. If the ischemic area is not known,
leads V3 and III are recommended to detect ST segment ischemia.



PTS: 1 DIF: Cognitive Level: Understanding REF: p.
246 OBJ: Nursing Process Step: Assessment TOP:
Cardiovascular MSC: NC LEX: Physiologic Integrit y

,2. A patient’s bedside electrocardiogram (ECG) strips show the following
changes: increased PR interval; increased QRS width; and tall, peaked T
waves. Vital signs are temperature 98.2° F; heart rate 118 beats/min;
blood pressure 146/90 mm Hg; and respiratory rate 18 breaths/min. The
patient is receiving the following medications: digoxin 0.125 mg PO every
day; D51/2 normal saline with 40 mEq potassium chloride at 125 m L/h;
Cardizem at 30 mg PO q8h; and aldosterone at 300 mg PO q12h. The
practitioner is notified of the ECG changes. What orders should the nurse
expect to receive?
a. Change IV fluid to D51/2 normal saline and draw blood chemistry.
b. Give normal saline with 40 mEq of potassium chloride over a 6 -hour
period.
c. Hold digoxin and draw serum digoxin level.
d. Hold Cardizem and give 500 mL normal saline fluid challenge over
a 2-hour period.



ANS: A



The electrocardiographic (ECG) changes are most consistent with
hyperkalemia. Removing the potassium from the intravenous line and
drawing laboratory values to check the potassium level is the best
choice with the least chance of further harm. Digoxin toxicit y can be
suspected related to the prolonged PR interval, but hyperkalemia
explains all the ECG changes. The patient is not hypotensive or
bradycardic, so holding the Cardizem is not indicated.



PTS: 1 DIF: Cognitive Level: Appl ying REF: p. 269
OBJ: Nursing Process Step: Intervention TOP:
Cardiovascular MSC: NCLEX: Physiologic Integrit y

,3. A patient with a serum potassium level of 6.8 mEq/L may exhibit what
type of electrocardiographic changes?
a. A prominent U wave
b. Tall, peaked T waves
c. A narrowed QRS
d. Sudden ventricular dysrhythmias



ANS: B



Normal serum potassi um levels are 3.5 to 4.5 mEq/ L. Tall, narrow
peaked T waves are usuall y, although not uniquel y, associated with
earl y hyperkalemia and are followed by prolongation of the PR
interval, loss of the P wave, widening of the QRS complex, heart
block, and asystole. Severel y elevated serum potassium (greater than 8
mEq/L) causes a wide QRS tachycardia.



PTS: 1 DIF: Cognitive Level: Remembering REF: p. 269
OBJ: Nursing Process Step: Assessment TOP:
Cardiovascular MSC: NC LEX: Physiologic Integrit y



4. Which serum lipid value is a significant predictor of fut ure acute
myocardial infarction (MI) in persons with established coronary artery
atherosclerosis?
a. High-densit y lipoprotein (HDL)
b. Low-densit y lipoprotein (LDL)
c. Trigl ycerides
d. Very-low-densit y lipoprotein



ANS: B

, Both the LDL-C and total serum cholesterol le vels are directl y
correlated with risk for coronary artery disease, and high levels of each
are significant predictors of future acute myocardial infarction in
persons with established coronary artery atherosclerosis. LDL -C is the
major atherogenic lipopro tein and thus is the primary target for
cholesterol -lowering efforts.



PTS: 1 DIF: Cognitive Level: Understanding REF: p.
274 OBJ: Nursing Process Step: Assessment TOP:
Cardiovascular MSC: NC LEX: Physiologic Integrit y



5. A patient with a potassium level of 2.8 mEq/L is given 60 mEq over a 12 -
hour period. A repeat potassium level is obtained, and the current
potassium level is 3.2 mEq/L. In addition to administering additional
potassium supplements, what intervention should now be considered?
a. Discontinue spironolactone
b. Drawing a serum magnesium level
c. Rechecking the potassium level
d. Monitoring the patient’s urinary output



ANS: B



The patient should have serum magnesium level drawn.
Hypomagnesemia is commonl y associated with other electrol yte
imbalances, most notabl y alterations in potassium, calcium, and
phosphorus. Low serum magnesium levels can result from many causes.



PTS: 1 DIF: Cognitive Level: Appl ying REF: p. 270 |
p. 271 OBJ: Nursing Process Step: Intervention